How to create a wind turbine blade using Surface Lofts

Ever wondered how to model one of those wind turbine blades you see dotted along the Scottish countryside? Well now you can! At first glance the turbine blades can look intimidating to create but with these simple steps you will be able to craft one with no problem. The primary aim of this blog is to demonstrate a range of surfacing tools in relation to creating complex shapes similar to this wind turbine feature. Wind turbine blades comes in a variety of shapes and sizes – from small 10 meter DIY garden turbines to large-scale offshore wind turbines with the rotor diameter of 190 metres (that’s a wing span of around 6 double decker buses!). So to craft this complex wing shape, the Spline feature (tools > sketch entities > spline) makes this easy due to its flexible nature which is user-friendly to draft out the desired shape. Following this, Geometry Planes (insert > reference geometry > plane) should be utilised to provide a guided cross-section to generate the wing blade form. These planes should be placed along the previously created sketch lines and position each plane in a perpendicular relation to the sketch line as visualised in the following image. Top tip: increasing the number of cross-section planes with sketches will increase the accuracy of the wing-blade shape (for demonstration purposes only a few planes are utilised) Blade shapes are then sketched upon each plane in accordance to the relevant specifications of wind-blade type. Prior to using surfacing features it is best practice to utilise the Split Entities Tool (tools > sketch tools > split entities) to break the specific shapes into segments. This step is important to ensure a smooth uniform transition will occur in tandem with the surfacing tools in later steps. At this point the sketching phase of this model is now complete to form a reference for the surfacing tools to form the main geometry. Firstly, using the primary surfacing tool of Surface Loft (Insert > Surface > Loft) will exploit the interpolating planes between the carious cross-sections created earlier. This is the best tool in this case for creating complex and organic forms, it should be noted however that Surface Loft will not create solid part at this point (as per usual for most surfacing features and entities) Top tip: Upon initiating the surface loft tool it is good practice to bring up a selection tool. Right click anywhere on the background and select the Selection Manager to help select surfaces as shown The profiles to be selected for the Surface Loft tool should be represented by the two main spline sketches and utilised as the foundation to create this lofted geometry. Moreover, the guide curves should be pre-selected to enforce the surface loft shape as it is guided through the spline profile. Next, confirm the selection to produce lofted surface (shown below). It should be noted that only half of the wing blade is fabricated – the Surface Loft tool should be repeated for the opposite side (shown below) to generate the full wing blade section. Despite having a full surface loft, the wing blade geometry has not yet fully formed. The Planar Surface Tool (Insert > Surface > Planar Surface) enables surface geometries to be enclosed. Although the shape is enclosed; surfaces do not generate a solid form therefore any surface parts have a seemingly ‘hollow shell’ when complete. In some cases this is acceptable for aesthetical presentation models, however if for instance there is a need to simulate a surfaced part model then the shape mass properties will be inaccurate and impractical to generate a simulation analysis. To compensate this, it is ideal to transition this into a full solid form using the Knit Surface tool (Found in insert > surface > knit surface). It is particularly important to make sure both options ‘try to form solid’ and ‘merge entities’ are selected, in order to fully seal the surface edges and provide mass within the enclosed surface shape. Upon completion of the surfacing tools, a finishing feature can be added to fully complete the wing blade part. By using the Dome feature (Insert > features > dome) to include the addition blade tip. Note: ensure the ‘continuous dome’ option is unselected to provide proportional dome geometry to the wing blade shape. The final resualtant wing blade part is shown below in its full solid form. In addition, the wing blade is also applied the full wind turbine assembly to visualise its potential applications. Furthermore, the completed part can be applied to full model for simulation or for aesthetical presentation uses. Thank you for taking your time to read my blog entry and I hope you have enjoyed following my summarised guide. It is hoped that features demonstrated can be applied to your personal work and be useful to build upon your Solidworks knowledge.

***

Andrew Tsim is an Applications Engineer at TMS CADCentre, a SOLIDWORKS Value Added Reseller in Scotland. You can read more from Andrew on the TMS CADCentre blog

TMS CADCentre - is a SOLIDWORKS Reseller based in Scotland providing 3D CAD Design Software, analysis software & product data management software. The company was formed in 1981 and now pleased to be celebrating 36 years in business. TMS CADCentre is the only UK SOLIDWORKS Reseller based and funded within Scotland and have been providing SOLIDWORKS software, training and support since 1996 when the product was first launched in the UK.